Human subjects are placed in a diffuse sound field for durations as short as 8 hours and as long as 48 hours. Auditory measurements are made before the exposure, during quiet periods interspersed within an exposure, and after the exposure. The major objective is to specify qualitative and quantitative relations between physical characteristics of the noise and the resultant (temporary) hearing loss. Of especial interest is a quantitative description of the growth and decay of threshold shifts, the relation between noise level and hearing loss, and the applicability of the equivalent power model of noise-induced hearing loss. BIBLIOGRAPHIC REFERENCES: Saunders, J.C., Mills, J.H., and Miller, J.D. (1977). "Threshold Shifts in Chinchilla from Daily Exposure to Noise for Six Hours," J. Acoust. Soc. Amer. 61, 558-570. Mills, J.H., Gilbert, R.M., and Adkins, W.Y. (1976). "Auditory Effects of 24-hour Exposures to Noise," J. Acoust. Soc. Amer. 60, S104 (A).